288 lines
9.2 KiB
C
288 lines
9.2 KiB
C
/* altair_sys.c: MITS Altair system interface
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(C) Copyright 1997 by Charles E. Owen
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Commercial use prohibited
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*/
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#include <ctype.h>
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#include "altair_defs.h"
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extern DEVICE cpu_dev;
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extern DEVICE dsk_dev;
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extern UNIT cpu_unit;
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extern REG cpu_reg[];
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extern DEVICE sio_dev;
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extern DEVICE ptr_dev;
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extern DEVICE ptp_dev;
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extern DEVICE lpt_dev;
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extern unsigned char M[];
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extern int32 saved_PC;
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extern char *get_glyph (char *cptr, char *gbuf, char term);
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extern unsigned int32 get_uint (char *cptr, int32 radix, unsigned int32 max,
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int32 *status);
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/* SCP data structures
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sim_name simulator name string
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sim_PC pointer to saved PC register descriptor
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sim_emax number of words needed for examine
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sim_devices array of pointers to simulated devices
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sim_stop_messages array of pointers to stop messages
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sim_load binary loader
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*/
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char sim_name[] = "Altair 8800";
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REG *sim_PC = &cpu_reg[0];
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int32 sim_emax = 4;
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DEVICE *sim_devices[] = { &cpu_dev, &sio_dev, &ptr_dev,
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&ptp_dev, &dsk_dev, NULL };
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const char *sim_stop_messages[] = {
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"Unknown error",
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"Unknown I/O Instruction",
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"HALT instruction",
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"Breakpoint",
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"Invalid Opcode" };
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static const char *opcode[] = {
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"NOP", "LXI B", "STAX B", "INX B", /* 000-003 */
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"INR B", "DCR B", "MVI B", "RLC", /* 004-007 */
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"???", "DAD B", "LDAX B", "DCX B", /* 010-013 */
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"INR C", "DCR C", "MVI C", "RRC", /* 014-017 */
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"???", "LXI D", "STAX D", "INX D", /* 020-023 */
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"INR D", "DCR D", "MVI D", "RAL", /* 024-027 */
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"???", "DAD D", "LDAX D", "DCX D", /* 030-033 */
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"INR E", "DCR E", "MVI E", "RAR", /* 034-037 */
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"???", "LXI H", "SHLD", "INX H", /* 040-043 */
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"INR H", "DCR H", "MVI H", "DAA", /* 044-047 */
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"???", "DAD H", "LHLD", "DCX H", /* 050-053 */
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"INR L", "DCR L", "MVI L", "CMA", /* 054-057 */
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"???", "LXI SP", "STA", "INX SP", /* 060-063 */
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"INR M", "DCR M", "MVI M", "STC", /* 064-067 */
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"???", "DAD SP", "LDA", "DCX SP", /* 070-073 */
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"INR A", "DCR A", "MVI A", "CMC", /* 074-077 */
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"MOV B,B", "MOV B,C", "MOV B,D", "MOV B,E", /* 100-103 */
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"MOV B,H", "MOV B,L", "MOV B,M", "MOV B,A", /* 104-107 */
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"MOV C,B", "MOV C,C", "MOV C,D", "MOV C,E", /* 110-113 */
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"MOV C,H", "MOV C,L", "MOV C,M", "MOV C,A", /* 114-117 */
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"MOV D,B", "MOV D,C", "MOV D,D", "MOV D,E", /* 120-123 */
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"MOV D,H", "MOV D,L", "MOV D,M", "MOV D,A", /* 124-127 */
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"MOV E,B", "MOV E,C", "MOV E,D", "MOV E,E", /* 130-133 */
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"MOV E,H", "MOV E,L", "MOV E,M", "MOV E,A", /* 134-137 */
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"MOV H,B", "MOV H,C", "MOV H,D", "MOV H,E", /* 140-143 */
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"MOV H,H", "MOV H,L", "MOV H,M", "MOV H,A", /* 144-147 */
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"MOV L,B", "MOV L,C", "MOV L,D", "MOV L,E", /* 150-153 */
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"MOV L,H", "MOV L,L", "MOV L,M", "MOV L,A", /* 154-157 */
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"MOV M,B", "MOV M,C", "MOV M,D", "MOV M,E", /* 160-163 */
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"MOV M,H", "MOV M,L", "HLT", "MOV M,A", /* 164-167 */
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"MOV A,B", "MOV A,C", "MOV A,D", "MOV A,E", /* 170-173 */
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"MOV A,H", "MOV A,L", "MOV A,M", "MOV A,A", /* 174-177 */
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"ADD B", "ADD C", "ADD D", "ADD E", /* 200-203 */
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"ADD H", "ADD L", "ADD M", "ADD A", /* 204-207 */
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"ADC B", "ADC C", "ADC D", "ADC E", /* 210-213 */
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"ADC H", "ADC L", "ADC M", "ADC A", /* 214-217 */
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"SUB B", "SUB C", "SUB D", "SUB E", /* 220-223 */
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"SUB H", "SUB L", "SUB M", "SUB A", /* 224-227 */
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"SBB B", "SBB C", "SBB D", "SBB E", /* 230-233 */
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"SBB H", "SBB L", "SBB M", "SBB A", /* 234-237 */
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"ANA B", "ANA C", "ANA D", "ANA E", /* 240-243 */
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"ANA H", "ANA L", "ANA M", "ANA A", /* 244-247 */
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"XRA B", "XRA C", "XRA D", "XRA E", /* 250-253 */
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"XRA H", "XRA L", "XRA M", "XRA A", /* 254-257 */
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"ORA B", "ORA C", "ORA D", "ORA E", /* 260-263 */
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"ORA H", "ORA L", "ORA M", "ORA A", /* 264-267 */
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"CMP B", "CMP C", "CMP D", "CMP E", /* 270-273 */
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"CMP H", "CMP L", "CMP M", "CMP A", /* 274-277 */
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"RNZ", "POP B", "JNZ", "JMP", /* 300-303 */
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"CNZ", "PUSH B", "ADI", "RST 0", /* 304-307 */
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"RZ", "RET", "JZ", "???", /* 310-313 */
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"CZ", "CALL", "ACI", "RST 1", /* 314-317 */
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"RNC", "POP D", "JNC", "OUT", /* 320-323 */
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"CNC", "PUSH D", "SUI", "RST 2", /* 324-327 */
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"RC", "???", "JC", "IN", /* 330-333 */
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"CC", "???", "SBI", "RST 3", /* 334-337 */
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"RPO", "POP H", "JPO", "XTHL", /* 340-343 */
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"CPO", "PUSH H", "ANI", "RST 4", /* 344-347 */
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"RPE", "PCHL", "JPE", "XCHG", /* 350-353 */
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"CPE", "???", "XRI", "RST 5", /* 354-357 */
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"RP", "POP PSW", "JP", "DI", /* 360-363 */
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"CP", "PUSH PSW", "ORI", "RST 6", /* 364-367 */
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"RM", "SPHL", "JM", "EI", /* 370-373 */
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"CM", "???", "CPI", "RST 7", /* 374-377 */
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};
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int32 oplen[256] = {
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1,3,1,1,1,1,2,1,0,1,1,1,1,1,2,1,0,3,1,1,1,1,2,1,0,1,1,1,1,1,2,1,
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0,3,3,1,1,1,2,1,0,1,3,1,1,1,2,1,0,3,3,1,1,1,2,1,0,1,3,1,1,1,2,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1,1,3,3,3,1,2,1,1,1,3,0,3,3,2,1,1,1,3,2,3,1,2,1,1,0,3,2,3,0,2,1,
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1,1,3,1,3,1,2,1,1,1,3,1,3,0,2,1,1,1,3,1,3,1,2,1,1,1,3,1,3,0,2,1 };
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/* This is the binary loader. The input file is considered to be
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a string of literal bytes with no format special format. The
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load starts at the current value of the PC.
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*/
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int32 sim_load (FILE *fileref, char *cptr, char *fnam, int flag)
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{
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int32 i, addr = 0, cnt = 0;
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if ((*cptr != 0) || (flag != 0)) return SCPE_ARG;
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addr = saved_PC;
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while ((i = getc (fileref)) != EOF) {
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M[addr] = i;
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addr++;
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cnt++;
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} /* end while */
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printf ("%d Bytes loaded.\n", cnt);
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return (SCPE_OK);
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}
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/* Symbolic output
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Inputs:
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*of = output stream
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addr = current PC
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*val = pointer to values
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*uptr = pointer to unit
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sw = switches
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Outputs:
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status = error code
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*/
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int32 fprint_sym (FILE *of, int32 addr, unsigned int32 *val,
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UNIT *uptr, int32 sw)
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{
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int32 cflag, c1, c2, inst, adr;
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cflag = (uptr == NULL) || (uptr == &cpu_unit);
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c1 = (val[0] >> 8) & 0177;
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c2 = val[0] & 0177;
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if (sw & SWMASK ('A')) {
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fprintf (of, (c2 < 040)? "<%03o>": "%c", c2);
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return SCPE_OK; }
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if (sw & SWMASK ('C')) {
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fprintf (of, (c1 < 040)? "<%03o>": "%c", c1);
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fprintf (of, (c2 < 040)? "<%03o>": "%c", c2);
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return SCPE_OK; }
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if (!(sw & SWMASK ('M'))) return SCPE_ARG;
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inst = val[0];
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fprintf (of, "%s", opcode[inst]);
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if (oplen[inst] == 2) {
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if (strchr(opcode[inst], ' ') != NULL)
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fprintf (of, ",");
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else fprintf (of, " ");
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fprintf (of, "%o", val[1]);
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}
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if (oplen[inst] == 3) {
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adr = val[1] & 0xFF;
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adr |= (val[2] << 8) & 0xff00;
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if (strchr(opcode[inst], ' ') != NULL)
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fprintf (of, ",");
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else fprintf (of, " ");
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fprintf (of, "%o", adr);
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}
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return -(oplen[inst] - 1);
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}
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/* Symbolic input
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Inputs:
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*cptr = pointer to input string
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addr = current PC
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*uptr = pointer to unit
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*val = pointer to output values
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sw = switches
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Outputs:
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status = error status
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*/
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int32 parse_sym (char *cptr, int32 addr, UNIT *uptr, unsigned int32 *val, int32 sw)
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{
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int32 cflag, i = 0, j, r;
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char gbuf[CBUFSIZE];
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cflag = (uptr == NULL) || (uptr == &cpu_unit);
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while (isspace (*cptr)) cptr++; /* absorb spaces */
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if ((sw & SWMASK ('A')) || ((*cptr == '\'') && cptr++)) { /* ASCII char? */
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if (cptr[0] == 0) return SCPE_ARG; /* must have 1 char */
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val[0] = (unsigned int) cptr[0];
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return SCPE_OK; }
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if ((sw & SWMASK ('C')) || ((*cptr == '"') && cptr++)) { /* ASCII string? */
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if (cptr[0] == 0) return SCPE_ARG; /* must have 1 char */
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val[0] = ((unsigned int) cptr[0] << 8) + (unsigned int) cptr[1];
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return SCPE_OK; }
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/* An instruction: get opcode (all characters until null, comma,
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or numeric (including spaces).
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*/
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while (1) {
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if (*cptr == ',' || *cptr == '\0' ||
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isdigit(*cptr))
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break;
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gbuf[i] = toupper(*cptr);
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cptr++;
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i++;
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}
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/* Allow for RST which has numeric as part of opcode */
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if (toupper(gbuf[0]) == 'R' &&
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toupper(gbuf[1]) == 'S' &&
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toupper(gbuf[2]) == 'T') {
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gbuf[i] = toupper(*cptr);
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cptr++;
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i++;
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}
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/* Allow for 'MOV' which is only opcode that has comma in it. */
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if (toupper(gbuf[0]) == 'M' &&
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toupper(gbuf[1]) == 'O' &&
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toupper(gbuf[2]) == 'V') {
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gbuf[i] = toupper(*cptr);
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cptr++;
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i++;
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gbuf[i] = toupper(*cptr);
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cptr++;
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i++;
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}
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/* kill trailing spaces if any */
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gbuf[i] = '\0';
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for (j = i - 1; gbuf[j] == ' '; j--) {
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gbuf[j] = '\0';
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}
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/* find opcode in table */
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for (j = 0; j < 256; j++) {
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if (strcmp(gbuf, opcode[j]) == 0)
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break;
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}
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if (j > 255) /* not found */
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return SCPE_ARG;
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val[0] = j; /* store opcode */
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if (oplen[j] < 2) /* if 1-byter we are done */
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return SCPE_OK;
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if (*cptr == ',') cptr++;
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cptr = get_glyph(cptr, gbuf, 0); /* get address */
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sscanf(gbuf, "%o", &r);
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if (oplen[j] == 2) {
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val[1] = r & 0xFF;
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return (-1);
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}
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val[1] = r & 0xFF;
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val[2] = (r >> 8) & 0xFF;
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return (-2);
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}
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